The Three Main Types of Conjunctivitis
Conjunctivitis is a common condition that occurs when either a viral or bacterial infection or an allergic reaction causes redness or inflammation in the conjunctiva — the clear tissue that covers the white part of your eye and the inside of your eyelids. Conjunctivitis is more commonly known as pink eye because it causes the white part of your eye to become pink or red.
Below, we explain the causes and symptoms of the different types of pink eye, when you should see an eye doctor, and what you can do at home to find some relief.
How Do You Get Pink Eye?
There are three main types of conjunctivitis: viral, bacterial, and allergic. However, conjunctivitis can also be caused by irritants, such as a foreign body in the eye, chemicals, or pollutants.
Viral infections cause nearly 80% of all conjunctivitis cases. Many different viruses, such as adenovirus, which typically leads to the common cold, can be the source of infection. Viral conjunctivitis spreads easily via touch from person to person, making outbreaks common among children in schools or daycare centers.
Although more rare, bacterial infections can also cause conjunctivitis. Types of bacteria that cause pink eye include:
- Staphylococcus aureus
- Streptococcus pneumoniae
- Haemophilus influenzae
- Moraxella catarrhalis
- Chlamydia trachomatis
- Neisseria gonorrhoeae
Bacterial conjunctivitis also spreads easily by touch, either through hand-to-eye contact or hand-to-nose contact. It can also thread through improper contact lens use.
According to the Centers for Disease Control (CDC) and Prevention, this type of pink eye is more common in adults than kids and occurs most frequently during the winter months (December through April).
Allergic reactions occur when your body responds abnormally to an allergen that is otherwise harmless. In this case, mast cells in your eye recognize allergens as foreign invaders and release a chemical called histamine as a defense mechanism. In turn, the histamine causes inflammation and swelling that leave your eyes red, teary, and itchy.
Allergens that cause a runny nose or sneezing can also affect your eyes. These allergens include pollen, dust, pet dander, mold, or smoke. Certain types of perfume, skin care or eye care products, or medications can also trigger eye allergies. For example, some over-the-counter or prescription eye drops have preservative chemicals that can cause allergic reactions.
Pink Eye Symptoms
Symptoms associated with each type of conjunctivitis may overlap, which can make it difficult to diagnose. These symptoms should only be used as a general guide. You should see an eye care professional for proper diagnosis and treatment.
Viral Conjunctivitis Symptoms
Common symptoms include red, burning eyes with watery discharge. Viral pink eye generally starts in one eye but can infect both eyes.
Bacterial Conjunctivitis Symptoms
Bacterial conjunctivitis results in a red, sore, or painful eye that emits a thick, yellow discharge (pus). There can be a significant amount of pus that may seem to flow despite continually wiping it away. The discharge can become thick enough to cause your eyelashes to stick together.
Allergic Conjunctivitis Symptoms
Eye allergies will cause your eye to become watery, itchy, red, and inflamed. It can also cause your eyelids to become puffy or make your eyes sensitive to light. These symptoms usually affect both eyes.
When Should You See a Doctor for Pink Eye?
Most cases of pink eye do not require a doctor, as complications are rare. However, it is important to call your eye care provider should you have any questions, concerns, or experience the following issues:
- Pain or issues seeing
- Sensitivity to light
- Symptoms that do not improve after a week or get worse
- The eye keeps producing pus or mucus
- Fever or achiness
Eye doctors are specifically trained to treat these types of eye issues. We encourage patients to turn to an ophthalmologist or optometrist for treatment as these doctors are more likely to properly identify the cause of pink eye and provide correct treatment.
A study in the American Academy of Ophthalmology (AAO) Journal researched 300,000 cases of acute conjunctivitis and found 83% of patients were initially diagnosed by primary care providers instead of ophthalmologists or optometrists and that a majority of these patients were incorrectly prescribed antibiotics, which will not help with most cases of pink eye. In fact, the study also revealed antibiotic-steroid drops are not needed for most patients with acute conjunctivitis because they may prolong or exacerbate certain infections.
How Is Pink Eye Treated?
There is no simple treatment for viral infections. You will have to rely on your immune system to get rid of viral conjunctivitis. It will usually take a week or two to go away. However, there are steps that can be taken to help with the recovery process, so please contact your eye doctor if you experience any of the complications listed above.
Mild cases of bacterial conjunctivitis may improve in two to five days — and typically completely go away within two weeks. But, in some cases, your eye doctor may prescribe antibiotic drops to help reduce the duration of infection, possibility of complications, and the chance of the infection spreading to other people. You may need antibiotic drops if you have discharge or a compromised immune system that cannot fight the infection on its own.
Allergic conjunctivitis will improve by removing the cause of the problem. For example, staying away from pets if you are allergic to cats or dogs. An ophthalmologist or optometrist can prescribe eye drops to relieve symptoms. An over-the-counter antihistamine can also provide relief.
What to Do for Pink Eye at Home
There are steps you can take on your own to reduce symptoms of viral and bacterial conjunctivitis. Over-the-counter lubricating eye drops, in particular, can help with inflammation and eye dryness. Preservative free drops can be used as frequently as every hour to help cope with the itching and burning of the eyes and minimize the urge to rub them.
A cool, damp washcloth placed over your eyes can also soothe your eyes and loosen dried mucus or pus. Just be sure to use a clean washcloth each time to avoid spreading the infection.
If needed, ibuprofen or other nonsteroidal anti-inflammatory drugs (NSAIDs) can be used with caution and for a limited period to provide pain relief and reduce inflammation. (Topical NSAID drops should be avoided).
For allergic conjunctivitis, antihistamine medications (either oral or eye drops) are the most effective way to relieve symptoms at home. Many allergy medications can now be bought over-the-counter. Lubricating eye drops or a cool, damp washcloth may also provide relief for watery, itchy eyes.
As for what not to do at home, avoid using redness-reducing drops such as Clear Eyes or Visine. These drops contain a decongestant that temporarily reduces swelling in your eyes’ blood vessels. But, when you have an infection, redness-reducing drops may cause discomfort or make symptoms worse. When using artificial tears, those purchased in a bottle may contain preservatives that can worsen symptoms if used more than four to six times a day. If using lubricating tears, preservative-free options are gentler on the eye and may help more with symptom relief.
How to Not Spread Pink Eye
As important as it is to care for your own conjunctivitis symptoms, you should also take precautions to avoid reinfecting yourself or spreading bacterial and viral conjunctivitis to others.
Wash your hands frequently with soap and water, especially before and after you eat, after using the restroom, or after touching your nose or mouth following a sneeze or cough. Pink eye symptoms may make it tempting to touch your eyes, but try to avoid doing so. Always wash your hands if you touch your eyes to avoid spreading the infection. If you are not careful, it is easy to spread pink eye from one eye to the other.
Frequently change anything that comes in contact with your eyes. Use fresh pillowcases, sheets, and towels daily.
Avoid using or sharing makeup while your eye is infected. Viruses can live in your cosmetic products, making it easy to reinfect yourself or infect others. Use new makeup when the infection clears up. If you wear contact lenses, do not use them until the conjunctivitis clears up and throw out any lenses that came in contact with the infected eye(s).